mean rate of reaction = quantity of reactant used / time taken

activation is the minimum energy for a collision to be successful

the steeper the gradient, the greater the rate of reaction - faster reaction, gradient decreases throughout reaction

what does the steepness of the gradient mean?

small lumps/powder - same volume but exposed SA increases - SA:v increases

which has a larger surface area - small lumps/powder, or large lumps?

greater frequency of successful collisions =

a catalyst is a substance that provides an alternative reaction pathway that has a lower activation energy than the uncatalysed reaction

a collision between reactant particles with enough energy (activation energy or more) to produce a reaction

how quickly a reactant is used up, or a product is formed

change in mass or volume throughout reaction

what can be measured to find the rate of reaction?

what does it mean on a time graph if the line becomes horizontal?

reactant particles become more crowded, frequency of collisions between reactant particles increases, rate of reaction increases (mean energy of particles doesn't change, just more collisions happen)

what happens if the concentration of the reacting solution or pressure of reacting gas is increased?

what is the result of a greater frequency of (successful) collisions?

the graph will have a steeper gradient and will finish (line becomes horizontal) sooner

more reactant particles exposed at surface, frequency of collisions between reactant particles increases, rate of reaction increases - mean energy of particles doesn't change

what will happen if there is a larger surface area of a substance/reactant?

which will have a greater rate of reaction - powder of large lumps?

rate of reaction increases, energy of particles increases, reactant particles move more quickly, proportion of collisions which are successful increases, frequency of successful collisions between reactant particles increases 

what happens if the temperature of a reaction mixture is increased?

increases the rate of reaction, doesn't change frequency of collisions, doesn't alter products of reaction, is not chemically changed/used up at the end of the reaction

because more particles have energy greater than the activation energy, because the activation energy was decreased by the catalyst

how does a catalyst increase the frequency of successful collisions?

no, and different substances catalyse different reactions

do all reactions have suitable catalysts?

flashcards on rate of reaction triple science chemistry

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GCSE AQA chemistry - rates of reaction

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GCSE AQA chemistry - rates of reaction

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